• Molecules and Cells
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• v.24 no.1
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• pp.83-94
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• 2007

During monocarpic senescence in higher plants, functional stay-green delays leaf yellowing, maintaining photosynthetic competence, whereas nonfunctional stay-green retains leaf greenness without sustaining photosynthetic activity. Thus, functional stay-green is considered a beneficial trait that can increase grain yield in cereal crops. A stay-green japonica rice 'SNU-SG1' had a good seed-setting rate and grain yield, indicating the presence of a functional stay-green genotype. SNU-SG1 was crossed with two regular cultivars to determine the inheritance mode and identify major QTLs conferring stay-green in SNU-SG1. For QTL analysis, linkage maps with 100 and 116 DNA marker loci were constructed using selective genotyping with $F_2$ and RIL (recombinant inbred line) populations, respectively. Molecular marker-based QTL analyses with both populations revealed that the functional stay-green phenotype of SNU-SG1 is regulated by several major QTLs accounting for a large portion of the genetic variation. Three main-effect QTLs located on chromosomes 7 and 9 were detected in both populations and a number of epistatic-effect QTLs were also found. The amount of variation explained by several digenic interactions was larger than that explained by main-effect QTLs. Two main-effect QTLs on chromosome 9 can be considered the target loci that most influence the functional stay-green in SNU-SG1. The functional stay-green QTLs may help develop low-input high-yielding rice cultivars by QTL-marker-assisted breeding with SNU-SG1.

• Korean journal of applied entomology
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• v.17 no.4 s.37
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• pp.193-199
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• 1978

Five parents and their 10 $F_1$ crosses of maize (Zea mays L.) were tested by means of diallel analysis for the inheritance of peroxidase activity following Puccinia sorghi rust infection. Peroxidase activity was measured at day zero and at 2 days and 8 days after inoculation. Peroxidase activity was increased significantly by P. sorghi infection in all 15 genotypes after 8 days, but not after 2 days. Highly significant differences in peroxidase activity were detected among the 15 genotypes. The highly genera] resistant inbred, CM105, and its hybrids showed exceptionally high peroxidase activity in both healthy and infected plants. However, another highly resistant inbred, Oh545, showed exceptionally low peroxidase activity. Significant general combining ability (GCA) and specific combining ability (SCA) means quares were detected for peroxidase activity independent of disease. GCA mean spuares, however, were consistently a major contiribution to the inheritance of peroxidase activity in the infected plants whereas SCA men square contributions were minor. Rust resistant maize plants controlling mongenic dominant $Rp_1^d$gene showed stronger peroxidase reroxidase responses than their susceptible counterparts in the gel electrophoresis and densiometric tracings. The increased peroxidase activity occurred in both major leaf peroxidases, $Px_3\;and\; Px_7$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.2
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• pp.146-150
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• 1990

This study was conducted to investigate the genetic analysis of esterase isozymes in maize with tillers. The materials used for the study were stele tissue for five day old seedlings of IK inbred line with tiller and A-type inbred line with no tiller, their Fl and F,. The methods employed for the study were same as previous report by Lee and Choe. A total of thirteen isoesterase enzyme bands were identified and five zones were distinguised according to both migration distance and genetic segregation patterns. The E$\sub$0.3/, E$\sub$0.4/ and E$\sub$0.5/ loci appeared from orgin to 0.5cm migration distance were controlled by the two alleles in (IK/A-type)F$_2$ and the E$\sub$0.3/+E$\sub$0.4/ of variants was controlled by codominant alleles. The E$\sub$1.0/, E$\sub$1.2/, E$\sub$1.5/ and E$\sub$1.8/ loci appeared from 1.0cm to 1.8cm were also controlled by the two alleles. However, the null band was functioned alleles. The E$\sub$2.8/, E$\sub$3.0/ and E$\sub$3.5/ loci appeared from 2.8cm to 3.5cm migration distance were very active and near location. A total of individuals with two paried bands of these loci were more than those of three paired bands(x$^2$=0.327$\^$**/). The activity of bands appeared over 3.8cm were very low and these were controlled by the two alleles. In above results, genetic segregations of stele tissue of maize with tillers were suggested to be controlled by Mendelian genetic laws.

• Horticultural Science & Technology
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• v.33 no.4
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• pp.575-584
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• 2015

Drought stress is a crucial environmental factor determining crop survival and productivity. The goal of this study was to clearly identify a new drought stress-tolerance gene in Brassica rapa. From KBGP-24K microarray data with the B. rapa ssp. pekinensis inbred line 'Chiifu' under drought stress treatment, a gene which was named BrDSR (B. rapa Drought Stress Resistance) was chosen among 738 drought-responsive unigenes. BrDSR function has yet to be determined, but its expression was induced over 6-fold by drought. To characterize BrDSR, the gene was isolated from B. rapa inbred line 'CT001' and found to contain a 438-bp open reading frame encoding a 145 amino acid protein. The full-length cDNA of BrDSR was used to construct an over-expression vector, 'pSL100'. Tobacco transformation was then conducted to analyze whether the BrDSR gene can increase drought tolerance in plants. The BrDSR expression level in T1 transgenic tobacco plants selected via PCR and DNA blot analyses was up to 2.6-fold higher than non-transgenic tobacco. Analysis of phenotype clearly showed that BrDSR-expressing tobacco plants exhibited more tolerance than wild type under 10 d drought stress. Taking all of these findings together, we expect that BrDSR functions effectively in plant growth and survival of drought stress conditions.

• Development and Reproduction
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• v.13 no.4
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• pp.305-312
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• 2009

Multipotent spermatogonial stem cells (mSSCs), derived from uni-potent SSC, are a type of reprogrammed cells with similar characteristics to embryonic stem cells (ESCs). The aim of this study was to evaluate the potential for transgenesis of mSSC derived from outbred mice and the production of transgenic animal by the mSSC-insertion into embryo. mSSCs, established from outbred mice (ICR strain) in the previous study, were maintained and then transfected with a lenti-viral vector expressing green fluorescent protein (GFP), CS-CDF-CG-PRE. Embryonic stem cells (ESCs) were derived from inbred transgenic mice (C57BL/6-Tg (CAG-EGFP)) and were used as an experimental control. Transfected mSSCs were well proliferated in vitro and maintained their characteristics and normal karyotype. Ten to twelve mSSCs and ESCs were collected and inserted into perivitelline space of 8-cell mouse embryos, and then transferred them into uteri of poster mothers after an additional 2-days of culture. Percentage of mSSC-derived offsprings was 4.8% (47/980) and which was lower than those (11.7% (67/572)) of ESC-derived ones (P<0.05). However, even though different genetic background of mSSC and ESC origin, the production efficiency of coat-colored chimeric offspring in mSSC group was not different when compared it with ESC (6.4% (3/47) vs. 7.5% (5/67)). From these results, we confirmed that mSSC derived from outbred mice has a pluripotency and a potential to produce chimeric embryos or mice when reaggregatation with mSSC is performed.

• The Plant Pathology Journal
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• v.19 no.2
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• pp.111-116
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• 2003

Turnip mosaic Potyvirus (TuMV) and Ribgrass mosaic Tobamovirus (RMV) are major viruses infecting crucifer crops in Korea. RMV-FG22 was isolated from oriental cabbage. TuMV isolates were TuMV-CA7 from oriental cabbage, TuMV-TU and TuMV-TU2 from turnip, TuMV-RA from rape, TuMV-ST from stock, and TuMV-R9 from radish. The six isolates of TuMV were classified by symptom expression in inbred lines of crucifers. TuMV-CA7 and TuMV-TU isolates infected mostly oriental cabbages; TuMV-ST, TuMV-TU2, and TuMV-R9 infected radishes; and TuMV-RA infected both oriental cabbages and radishes. Crops used in six combinations of mixed infections were 'Tambok' cultivar resistant to TuMV,'SSD63' susceptible inbred line of oriental cabbage, pure line of leaf mustard, and‘Daeburyungyeorum’cultivar of radish. External symptoms in 'Tambok' and radish by each of the six single infections of TuMV showed similar results by bioassay. Synergistic response of necrotic death occurred within 1 week after inoculation in all combinations mixed with TuMV and RMV-FG22 on leaf mustard. In oriental cabbage 'SSD63' , synergism of necrosis occurred in four TuMV isolates, but not in TuMV-ST and TuMV-R9. In oriental cabbage 'Tambok' , synergism was expressed only in two combinations of RMV-FG22+TuMV-CA7 and RMV-FG22+TuV-TU, but other combinations had the same symptoms produced by RM-FG22. In radish‘Daeburyungyeorum’, only mild mosaic symptoms were induced by combinations of RMV-FG22+TuMV-CA7, RMV-FG22+TuMV-TU, RMV-FG22+TuMV-RA, and RMV-FG22+TuMV-R9. Mosaic and severe mosaic were induced in combinations of RMV-FG22 +TuMV-TU2 and RMV-FG22+TuMV-ST, respectively.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.917-921
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• 2014

'Hei-G' is a new tomato cultivar originating from the cross of two inbred lines, the maternal plant TKUI-3 separated from 'Kame' in 2007, and the paternal plant AL-1 developed by pedigree breeding. The new cultivar was registered as 'Hei-G' named 'JTB026 (Jeonnam-2)' based on characteristics and yield trials carried out in the spring of 3 years, from 2010 to 2012. 'Hei-G' is an indeterminate type with strong plant vigor. The fruit is round and the ripening fruit is blackish red. The average fruit weight of 'Hei-G' is about 43.4 g, and its marketable yield is $4,944kg{\cdot}10a^{-1}$. The lycopene content of 'Hei-G' ($11.8mg{\cdot}100g^{-1}$) is higher than that of other tomatoes (e.g., cv. Rapido, 3.1 mg). In addition, 'Hei-G' is suitable for environment-friendly protected cultivation because of its resistance to powdery mildew.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.833-836
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• 2013

'Hei' is a new cultivar of red with black flesh; originated from the cross of two inbred lines, mother plant, TKUI separated from 'Kame' in 2007 and father plant, TLB separated from tomato collected in Europe by pedigree breeding method. 'Hei' was tested for specific character and productivity of lines of tomatoes in spring for 2 years, 2008 to 2009. This variety had resistance to powdery mildew. 'Hei' is an indeterminate type. The fruit shape is round and the skin color is blackish red. The average fruit weight of 'Hei' is about 127.9 g and marketable yield is $5,715kg{\cdot}10a^{-1}$. Lycopene contents of 'Hei' are about $18.5mg{\cdot}100g^{-1}$, high compared with other tomato ($3.1mg{\cdot}100g^{-1}$). 'Hei' is suitable for environment-friendly protected cultivation because of resistance to powdery mildew.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.1
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• pp.41-49
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• 2016

This study was conducted to evaluate maize downy mildew resistance using spreader row technique in Cambodia. A total of forty maize lines were used in this experiment. Seven Korean varieties and seven breeding lines showed high infection rates (80~100%) and highly susceptible (HS) to downy mildew disease in both spring and fall. Also most of nested association mapping (NAM) parent lines were highly susceptible (HS). Meanwhile three inbred lines, Ki3, Ki11, and CML228, showed highly resistant (HR) or resistant (R) in spring and moderately resistant (MR) in fall. These three lines were already known as resistant inbred lines against downy mildew disease. It appears that spreader row technique was suitable for selection of maize downy mildew resistance in Cambodia. The incidence of downy mildew was influenced by weather conditions, especially relative humidity and temperature. Among several inoculation methods to screen for downy mildew resistance, this spreader row technique is effectively and easily used in the field of Southeast Asia.

• Journal of Embryo Transfer
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• v.28 no.4
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• pp.373-379
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• 2013

Spermatogonial stem cells (SSCs) developed into sperms through spermatogenesis have been utilized as a useful tool in the field of regenerative medicine and infertility. However, a small number of highly qualified SSCs are resided in the seminiferous tubule of testis, resulted in developing effective in-vitro culture system of SSCs for solving simultaneously quantitative and qualitative problems. Presently, SSCs can be enriched on testicular stromal cells (TSCs), but there are no systematic researches about TSC culture. Therefore, we tried to optimize culture condition of TSCs derived from mouse with different strains. For these, proliferation and viability were measured and compared by culturing ICR outbred or DBA/2 inbred mouse-derived TSCs at 35 or $37^{\circ}C$. In case of ICR strain, primary TSCs cultured at $37^{\circ}C$ showed significantly higher proliferation and viability than those at $35^{\circ}C$ and significant increase of proliferation and viability in sub-passaged TSCs was detected in the $35^{\circ}C$ culture condition. Moreover, sub-passage of primary TSCs at $35^{\circ}C$ induced no significant effects on proliferation and viability. In contrast, in case of DBA/2 strain, significantly improved proliferation were detected in the primary TSCs cultured at $35^{\circ}C$, which showed no significant difference in the viability, compared to those at $37^{\circ}C$. Furthermore, sub-passaged TSCs cultured at $37^{\circ}C$ showed no significant differences in proliferation and viability, compared to those at $35^{\circ}C$. However, with significant decrease of proliferation induced by sub-passage of primary TSCs at $35^{\circ}C$, no significant effects on proliferation and viability were resulted from sub-passage of primary TSCs at $37^{\circ}C$. From these results, culture temperature of primary TSCs derived from outbred and inbred strain of mouse could be separately optimized in primary culture and subculture.